DEPARTMENT OF COMMERCE 

BUREAU OF nSHERIES 

HUGH M. SMITH, Commissioner 



MORTALITY OF FISHES ON THE 
WEST COAST OF FLORIDA 



By Harden F* Taylor 

Scientific Assistant, Bureau of Fisheries 



APPENDIX III TO THE REPORT OF THE U. S. COMMISSIONER 
OF FISHERIES FOR 1917 




Bureau of Fisheries Document No. 848 



PRICE 5 CENTS 

Sold only by the Superintendent of Documents 
Government Printing Office, Washington, D. C. 



WASHINGTON 
GOVERNMENT PRINTING OFFICE 

1917 



Monograph 






0. of D. 

JUN 18 19U 



X 






CONTENTS 



Page. 

Occasion for the investigation 5 

Reports of the disaster in 1916 5 

Investigation in the field 8 

Species affected 9 

Meteorological conditions 11 

Examination of specimens 11 

Discussion of possible causes of this and similar disasters in other parts of the 

world 12 

Foul water from the Everglades 13 

Peridinium and other protists 14 

Disease and parasites 16 

Dilution of the water 17 

Volcanic and natural gases 17 

Earthquakes 19 

Alkalinity and salinity of the water 20 

Other mortalities due to obscure causes 21 

Summary and conclusions 22 

Bibliography. 23 

3 



MORTALITY OF FISHES ON THE WEST COAST OF FLORIDA* 



By Harden F. Tayloe, Scientific Assistant, Bureau of Fisheries. 



OCCASION FOR THE INVESTIGATION. 

Eepeatedly in the past 75 years reports have come from the west 
coast of Florida of " poison water," which killed fishes in large num- 
bers, and also, according to some reports, other animals, notably 
sponges. The reports and references are too fragmentary to give an 
accurate record of the distribution of the mortality, but collectively 
they clearly indicate that all the keys from Key West nearly as far 
north as Cedar Keys have been visited by this plague, and that it 
occurred in the years 1844, 1854, 1878, 1880, 1882, 1883, 1908, and 
finally in 1916. 

REPORTS OF THE DISASTER IN 1916. 

In October and November, 1916, the mortality recurred in severe 
form, the first visitation since 1908. Numerous descriptive reports 
were received, from which the following significant points were 
summarized : 

Fishes of a great number of species were noted dead and dying; 
the air was charged with a suffocating gas, which not only occasioned 
severe discomfort to man and other air-breathing animals, but irri- 
tated the air passages, producing the symptoms of colds. This gas, 
while exceedingly irritating, had no odor. The fishing smacks which 
are equipped with " wells " or openings through to the water in 
which live fish are kept report that the whole catch died while the 
smacks were en route to port; the normal color of the water had 
given way to water of different color, variously described as "black 
streaky," " amber," " olive," and " red" ; the white paint of certain 
houses near the water was temporarily blackened, apparently by 
gases from the enormous number of dying fish. Some local observers 
found fish dying in the sounds ; others noted them in the passes and 
in the Gulf to a distance of 45 miles out, but the abundance of fish 
in any locality varied from day to day. The reports of the order 

5 



6 MORTALITY OF FISHES, WEST COAST OF FLORIDA. 

in which the species appeared are not consistent, so it is assumed that 
there was no particular succession of species. The abnormal condi- 
tions seemed to be moving soutliAvard, occurring at Boca Grande on 
October 3 and 18, at Captiva Pass about the middle of October, at 
Blind Pass about October 20, at San Carlos Pass about November 1, 
and dead fish were first seen at Big Marco Pass on November 5. 
Captiva Pass is 7.5 statute miles south of Boca Grande Pass; the 
others are, respectively, 16.5, 27.75, and 67.75 miles to the south of 
Boca Grande Pass. The captain of the steamer Roamer^ of the 
Florida Shellfish Commission, reports that dead fish were seen as 
far south as Cape Eomano, about 128 miles south of Boca Grande. 
The death of two persons in Fort Myers, Fla., in November, was 
attributed to the eating of some of these dead fish. 

The following letters from George H. Skermer, deputy collector of 
customs at Boca Grande, describing the phenomenon, merit reproduc- 
tion here. Letter dated October 22, 1916, reads : 

I wish to call y'our attention to an unusual phenomenon which has occuri'ed 
on the Gulf coast during the past month, and which, so far as I am able to 
ascertain, has extended on the north to Sarasota and south to Naples, west- 
ward, from 15 to 20 miles. 

About October 3, large quantities of what are locally known as " red-mouth 
grunts " began to come ashore. These fish were normal in appearance, with the 
exception that many showed a tendency to have the eyes almost forced out 
of their sockets. The early morning of the third the Gulf was covered with 
these fish as far as the eye could see. Later in the day many other varieties 
began to drift in, and by night what might be styled windrows of them were 
lying along the beach. Among them were many fish altogether strange to us ; 
among the known varieties were mackerel, jacks, small shark, porktish, sheeps- 
head, toadfish (several varieties), mangrove snappers, grouper, sardines, sea- 
horse, cowfish, remora, moray, eels, mullet, pinfish, gurnards, ladyfish, grunts, 
and many other varieties, not all of which showed the tendency to "popeye." 

Soon after this drift commenced I went to the beach accompanied by a small 
dog; while on the beach I felt a slight tendency to sneeze and cough; shortly 
afterwards my attention was called to the action of the dog which was sneezing 
violently and seemed to be in acute distress, choking and showing every symp- 
tom of asphyxiation. I carried him off the beach and in a short time he seemed 
to recover, so I carried him back, and the same thing happened again. I then 
noticed that my lungs were feeling sore and that my breathing was labored, in 
much the same manner as when I board ships after fumigation, except that I 
could notice no odor. Other people were affected the same way. 

Later in the day the captain of the Cuban fishing smack Rafaela Pedre, which 
liad run into the harbor for water after a 45-day trip, come to the office and 
told me that his entire catch of grouper and snapper had died almost imme- 
diately after the tide started in. I questioned him carefully and found that 
they had noticed the peculiar sensation I have above described. The next day 
another smack came in with her fish dead and reported that dead fish covered 
the Gulf for miles out. The captain of the Dutch steamship Zeta, which arrived 
on the 8th, reported that he had passed through miles of dead fish. 

In a few days the plague abated, very few more coming In. 



MORTALITY OF FISHES, WEST COAST OF FLOEIDA. 7 

However, on the IStli another violent outbreak occurred, this being much 
more serious than the first, inasmuch as it had Ivilled many large fish which did 
not seem to be the case during the first attack. For the past few days the 
beach has been lined with tarpon, jewfish, grouper, and many varieties of top 
fish which seemed to escape the first attack. In addition to this, many of the 
bay fish are succumbing. The gas was very violent this time and many people 
telephoned for medical assistance for " cold in the head," " sore throats," " cold 
in the chest," etc., besides coming to see the local physician, who is also the 
United States quarantine surgeon here. I, myself, have suffered quite acutely 
for the past five days, but the worst of the gas seems to be going now. 

I tried the dog again, and again had to take him off. I do not think he would 
have been able to live over two hours on the beach. The fish died in a very 
short time. I observed a mullet dying yesterday ; as the tide came into the 
bayou the gas met him, he began to act strangely, coming to the top, whirling 
around and around, and then sank to the bottom, lying stomach up for a little 
while, when he turned on his side dead. Spadefish acted the same way. It is 
now reported that the fish are dying freely in the remote bays and bayous, 
every local variety seeming to give up its share. I have been told that many of 
the barnacles have also died, but I can not confirm this. I have noticed that 
the conchs and crabs are not dying, at least to any extent. * * * 

If you desire any other information as to this matter, I shall be glad to 
furnish it if it lies in my power. I meant to state that I noticed the pungent 
feeling of the gas particularly when a wave " broke " and believe that this will 
explain why the top fish escaped with less visible destruction than the bottom, 
the breaking of the wave aerating the water more or less. * * * 

The gas has none of the characteristics of H2S ; it acts with the same peculi- 
arity of chlorine, but is odorless, perhaps is CO2 ; addition of lead acetate to 
sea water gives a dense white precipitate, but am not sure but that it might do 
that normally, precipitating lead chloride. 

The " odorless but exceedingly irritating gas," as described, was 
not noted by the observer, but had, perhaps, already subsided. The 
protrusion of the eyeballs was due to the accumulation of gases from 
decay behind ,the orbits, as only those fishes which had been dead 
for some time were thus affected. 

A letter from Mr. Skermer, dated November 11, 1916, reads: 

I am in receipt of your letter of the 8th instant relative to the supposed 
presence in the Gulf waters of Perklinii in abnormal numbers. I wish to state 
that I have not been able to learn of such conditions obtaining nor have I 
noticed any marine growth of abnormal appearance at any time during the 
mortality periods. However, I have inquired carefully at every opportunity 
since the fish began to die from any person who I had reason to suppose 
had come in contact with the dying fish as to whether he had noticed any 
peculiarity in the water. I learned from two persons that the fish seemed 
to die in " streaks " and sometimes in dark-colored water ; others noticed nothing 
abnormal in the appearance of the water but did speak of the odorless but 
exceedingly irritating gas which seemed to be liberated at intervals. * * * 

This morning I inquired of a Spanish fisherman, who lives about 7 miles 
south of Boca Grande, as to conditions near him. He informed me that fish 
were still dying along the Captiva Pass and inside waters of Pine Island 
Sound. He further stated that the fish died when coming in contact with it. 
The dark-colored water he said was in the bays and did not enter the Gulf 
at all except at low water. From this I am inclined to believe that it is 



8 MORTALITY OP FISHES^ WEST COAST OF FLORIDA. 

simply an overflow of .swamp water, and do not believe that it is the cause of 
the mortality. 

The fish were killed many miles out in the Gulf. The captain of the Dutch 
steamer Themisto, which arrived here October 27, told me that he passed 
through imiuense numbers of dead fish 45 miles out. I asked him if he noticed 
anything abnormal in the appearance of the water, and he said " No." A 
fishing smack which entered here lost all its fish after entering the bay, 
and another reported that upon attempting to enter the bay saw its fish 
beginning to die, and that upon turning about and going into the Gulf they 
recovered. I can only reconcile the two circumstances in this way : For 
several days after the fish ceased dying in the Gulf they died in the bay, aud it 
is probable that the last-mentioned smack met the returning current from 
the bay to the Gulf, while the first-mentioned got it in full strength from the 
Gulf in the beginning of the attack, as he was anchored in the tidal channel. 

* if * 

INVESTIGATION IN THE FIELD. 

Conditions made it impossible to undertake a field investigation 
during the early stages of the mortality when it was at its worst, but 
the writer arrived at Fort Myers, Fla., on the Caloosahatchee River, 
November 12, and remained in the region for a period of 10 days. 

Since the mortality of the fishes had been ascribed to foul water 
from the Everglades, the condition of this river was first noted. No 
abnormal conditions were observed in the river; small fish were 
abundant; birds were feeding upon them. Schools of mullet and 
red drum ("redfish"), vast numbers of ducks, and many pelicans 
were seen on the river below Fort Myers. In no case was a dead 
water animal found on the river. The water was of a brownish color, 
due, presumably, to tannin or other pigments from the mangroves 
and palmettoes, but it is understood that such a condition is not un- 
favorable to fish. 

On the next day a reconnoissance trip w'as made on a river steamer 
from Fort Myers down the Caloosahatchee to Punta Rasa, thence 
across San Carlos Bay to Sanibel, across the bay again to St. James 
City, on Pine Island, thence across Pine Island Sound to Wulfert (in- 
side mouth of Blind Pass), then through a narrow channel to Cap 
tiva, returning the same day via Sanibel and Punta Rasa. Between 
Fort Myers and Punta Rasa (18 miles) the river appeared to be 
normal in every respect. In San Carlos Bay dead fishes were noted, 
blanched and soft, apparently having been dead for some time. On 
the inside beaches of Sanibel, Pine, and Captiva Islands dead fishes 
in great numbers and of a multitude of species were noted, all in a 
state of decay. 

On the return trip, near Sanibel Wharf, a specimen of squeteague 
{(Jynoscion nehulosus) was taken in a state of rigor mortis, but with- 
out apparent abnormality. 



U, S."B^ F— Doc. 



Plate I. 



MYERS 




BIG MARCO PASS (^ 



MAP SHOWING REGION WHERE MORTALITY OCCURRED. 



/^ 



U S. B. F.— Doc. 848 



Plate II. 




SAN CARLOS BEACH, SANIBEL ISLAND, NOVEMBER 19, 1916. 




GULF BEACH, SANIBEL ISLAND, NOVEMBER 19, 1916. 



MOETALITY OF FISHES, WEST COAST OF FLORIDA. 9 

Beginning the next day, Xoveniber 13, the writer spent three days 
in the vicinity of San Carlos Bay, with headquarters at SanibeL In 
this interval water samples were collected at various places in San 
Carlos Bay and Pass, Pine Island Sound, Tarpon Bay, and Blind 
Pass. Efl'orts made to collect bottom samples were successful only 
in obtaining pieces of shell and fragments of a thin layer of lime 
deposit which seems to cover the bottom in San Carlos Bay and Pine 
Island Sound. Such qualitative tests as were made indicated a 
rather strong alkalinity. On November 13 and 14 dead fishes were 
in greater abundance, coming in, apparently, on the tide. On the 
13th a census of dead fishes was taken covering 20 steps of the San 
Carlos Beach, Sanibel Island. This census revealed 163 specimens 
of fishes, of 26 species, and included neither the windrow cast up at 
high tide, nor those floating, but only those at or close to the water's 
edge. On the dark nights of that week the phosphorescence of the 
decaying fishes made the beach visible for a long distance, and the 
sand was so charged with phosphorescent bacteria that one's tracks 
persisted for some seconds. Familiar fishes were identified by their 
own light. The odor was ahnost intolerable ; people dwelling on the 
islands hauled away wagonloads and buried them in their orchards 
for fertilizer. 

SPECIES AFFECTED. 

In all the region covered the following species were noted : '^ 



Species. 



Conmionname. 



Family. 



Manta birostris b 

Ocyurus chrysurus >> . . 

Neomaenis griseus 

Epinephilus morio <> . . 

E. striatiis 

Garrupa nigrita 

Centropristes striatus. 

Menticirrhus sp.b 

Cynoscion nebmosus . . 
C. 



.sp. 



Bairdiella sp 

Pogonias cromis 

Scisenops ocellatus 

Tarpon atlanticus b 

Caranx hippos 

Caranx crysos 

Selene vomer 

Trachinotus carolinus . . 

Oligoplites saurus 

Scorpfena sp 

Mugil ceplialus 

Hsemiilon plumleri 

H. sciurus 

Bathystoma rrmator 

Anisotremus virginicus . 

Monacanthus sp 

Do 

Scomberomorus regalis. , 

Rissola marginata 

Scarus vetula 



Devilfish 

Yellow-tail 

Mangrove snapper 

Red grouper 

Nassau grouper 

Jewfish 

Sea bass 

Whiting 

Spotted squeteague ("trout") 

Squeteague ("trout ") 

Sand perch 

Black drum ("drum") 

Red drum, channel bass ("redflsh") . . 

Tarpon 

Crevalli? 

Crevall^ ("skip jack") 

Moonfish 

Pompano 

Leather jacket 

Scorpionflsh 

Mullet 

Grunt 

do 

Red-mouth grunt 

Porkflsh 

Fileflsh 

do 

Cero ; kingflsh 

Cusk eel 

Parrotflsh 



Mantidae. 
Lutianidse. 

Do. 
Serranidae . 

Do. 

Do. 

Do. 
Sciaenidse . 

Do. 

Do. 

Do. 

Do. 

Do. 
Elopidse. 
Carangidse. 

Do. 

Do. 

Do. 

Do. 
Scorpsenidse. 
Mugilidae. 
Haemulida^. 

Do. 

Do. 

Do. 
Monacanthidee. 

Do. 
Scombridae. 
Ophidiidse. " 
Scaridse. 

a The identifications here represented are, of course, open to question. Time did not admit of careful 
study. On the great majority of the fishes the colors had faded, of several species only badly decomposed 
specimens were seen, and some of the others were quite unfamiliar to the observer. 

b Not seen by writer, but reported by fishermen and others. 

87829—17 2 .T". 1 



10 



MORTALITY OF FISHES, WEST COAST OF FLOEIDA. 



Species. 



Common name. 



Family. 



Chaetodipterus f aber 

Archosargus probatocephalus . 

Otrynter caprinus 

Calamus sp 

Lycodontis (moringa?) 

L. (jordani?) 

Paralichthys sp 

Echeneis remora 

Clupanodon pseudohispanicus 

Brevoortia tyrannus 

ChEetodon ocellatus 

Angelichthys ciliaris 

Lactophrys' tricornis 

Lactophrys trigonus 

Prionotus sp 

Opsanus sp 

Spheroides sp 

Chilomycteriis spinosus 

Dasyatis (say?) i Sting ray 

Raja sp I Skate 



^tobatus narinari ! Spotted sting ray . 

Rhinobatus lentiginosus 

Felichthys f elis 

Galeichthys (milberti?) 

Hemirhamplius sp 



Spadeflsh Ephippidae. 

Sneepshead Spandae. 

Long-spine porgy Do. 

Porgy Do. 

Black moray Muraenidse. 

Spotted moray Do . 

Flounder Pleuronectidae. 

Remora, shark pilot Echeneididae. 

Sardine ("shiner") Clupeidae. 

Menhaden Do. 

Butterflyfish Chaetodontidae. 

Angelflsh Do. 

Trunlcflsh ("cowflsh") ! Ostraciidae. 

Trunkfish Do. 

Sea robin i Triglidae. 

Toadfish ' Batrachoididae. 

Puffer ("toadfish") I Tetraodontidae. 

Burr lish ! Diodontidae. 

Dasyatidae. 

Rajidae. 



Myliobatidae. 



Tylosurussp. 



Leptocephalus conger 

Sy nodus foetens 

Sphyrna tiburo 

Carcharinus (obscurus?) . 

Albula vulpes 

Ogcocephalus vespertilio . 



Guitar fish ] Rhino batidae. 

Gafl-topsail catfish ! Siluridae. 

Sea catfish Do. 

Half beak; needlefish Hemirham- 

phidae. 

Marine gar; needlefish j Belonidae. 

Small eel; whip eel ' Moringuidae? 

Conger eel I>eptocephalidse. 

Lizard fish Synodontidse. 



Shovel-nose shark. 

Shark 

Lady fish. 
Batflsh . . 



Sphyrnidae. 
Galeidae. 
Albulidae. 
Ogcocephalidae. 



Of invertebrates, sea urchins (Arhacia), the king, or horseshoe 
crab (Limuhcs) , and sponges were noted. It is a matter worth noting 
that very few animals other than fishes were killed. Barnacles, 
oysters, and mussels were examined, but they were in good condition. 
Live conchs and hermit crabs were repeatedly observed. Porpoises 
were plentiful during the period of observation. Pelicans and other 
water birds behaved normally. Buzzards were common in the lo- 
cality, yet they neglected the dead fish entirely. 

The dead fauna of the Gulf beach was not markedly different from 
that of the bays. Relatively more carangids, sharks, and rays were 
seen, but many of the dead forms were buried in the hard beach sand, 
hence the Gulf beach did not present such a striking picture as did 
the inside beaches. Taking the whole territory into consideration the 
relative abundance of the different species is estimated as follows in 
the order given, less abundant species being omitted : 

Grunt (Hwmulon plumieri) (H. sciurus). 

Mullet {Mugil ccphalus). 

Trunkfish (Lactophrys trigonus) (L. tricornis). 

Puffer (Spheroides sp. ). 

Menhaden (Brevoortia tyrannus). 

Sardine (Clupanodon pseudoMspanictts) . 

Red-mouth grunt (Bathystoma rimator) . 

Spadefish (Chwtodipterus faher). 

Moray (Lycodontis sp.). 

Filefish (Monacanthus ?). 

Sheepshead (Archosargus probatocephalus). 

Spotted squeteague (Cynoscion nebutosiis) . 



MORTALITY OF FISHES, WEST COAST OF FLORIDA. 11 

It is assumed that the numbers are representative of the relative 
abundance of these forms in life. The sizes of specimens would also 
suggest that all true fishes were killed, regardless of size. They 
range from jewfish of approximatel}^ 200 pounds to forms less than 
2 inches long. 

METEOROLOGICAL CONDITIONS. 

The temperature of the Avater was around 75° F. until November 15. 
On this date a violent " northwester "' blew up, occasioning a series 
of extraordinarily high and low tides. After this the temperature 
was 65° F., and continued at about that figure through the remainder 
of the observation period. Contrary to what might be expected, the 
mortality of fishes did not cease after the storm. In this connection 
it may be added that the wind had been blowing constantly from the 
northeast for several weeks previoush^ and, after the storm, shifted 
around to the northeast again. 

The water was olivaceous in color — about such a color as would be 
expected from a mixture of sea Avater with the brownish water of 
the rivers. Those accustomed to seeing the water stated that during 
the period of mortality the water was of a more brownish color than 
usual. The wake of the boats had an oily appearance, or was appar- 
ently not so effervescent as that in normal sea water. It was further 
stated that at the height of the mortality, on the Gulf coast, the water 
was of an amber color (by transmitted light). This colored water 
was described as being not uniformly distributed, but occurring in 
streaks, and it was in these streaks that the fish are said to have 
perished. A resident of the island described the death of a mullet 
thus : 

The fisherman was following a large mullet in Tarpon Bay (partly inclosed 
in Sanibel Island), intending to capture it with a cast net. The fish, at a depth 
of possibly 2 feet, seemed suddenly to strike a streak of the bad water, came 
rapidly to the surface, flipped from the water, and, after a short struggle, ex- 
pired. 

The exact spot, about 6 feet from shore, was visited by the observer, 
but nothing unusual was noted. Several dead mullets were seen 
ashore ; live porpoises and conchs were in the water. 

EXAMINATION OF SPECIMENS. 

On November 16 a mangrove snapper {Neomcenis griseus) was 
taken by a boatman in £l moribund condition. The writer first saw 
this fish a few minutes after it had died, and he at once dissected it. 
The blood was not yet coagulated, and, indeed, seemed less inclined 
to coagulate than one might expect. The fish was not infested with 
parasites, no lesions were noted, the gills were pink (perhaps too 
red), the stomach contents were small fish, clean and constituting an 



12 MORTALITY OF FISHES, WEST COAST OF FLORIDA. 

apparently wholesome food. The liver was slightly abnormal in 
appearance, being faintly mottled with a lighter shade of brown. 
The mucous covering of the body was transparent and colorless; 
none of the organs were distended by gas, nor were gas bubbles 
observed in the blood vessels. The eyes were clear, and no evidence 
of fungus was seen. The coloring of the fish was vigorous. 

Fishes in a moribund condition were reported as having been ob- 
served' in the passes, in the Gulf, and in Tarpon Bay, but since the 
carcasses drifted with wind and tide the mere presence of dead fish 
was not an indication of a mortality at any given place. The condi- 
tion sought for must have been immediately at hand, however, when 
a moribund fish was observed on November 19. 

It was a small filefish {Monacanthus sp.), and was first observed 
near the dock at Bailey's Wharf, Sanibel, in water not over 3 feet 
deep. The fish was brilliantly mottled with maroon on a slate- 
colored background. It was drifting upon its side, making but 
slight effort to balance. This fish was captured and placed in a 
bucket of the water from which the fish was taken. A moment later 
a small, active, pinfish was captured in the same place and likewise 
kept in another bucket with some of the same water. The color of 
the filefish faded, but repeatedly revived when the fish was disturbed ; 
each response, however, was weaker than the preceding one until the 
fish died, and the color faded in about 2 hours. The pinfish, taken at 
the same time and place, lived till it was released at Fort Myers, 
about 6 hours later. Both species had repeatedly been noted dead 
upon the beach. Within 50 feet of the point where the filefish was 
dying numerous mangrove-snappers and sheepshead were seen, quite 
healthy in appearance. So we have the anomalous condition of 
dying fish and perfectly healthy fish within 50 feet of each other 
and in the same water, with certain knowledge that all the species 
concerned are subject to destruction by the abnormality responsible 
for the death of so many species. 

Representations were made to the writer concerning the pollution 
of Peace River. This is a small sluggish stream, tributary to Char- 
lotte Harbor, and drains a region now being worked for phosphate 
rock. It was said that the waste from the works destroyed the fish. 
However true this may be, a brief visit only was necessary to show 
that such a pollution could have no bearing on the mortality under 
consideration. Small fish as well as vegetation were in the stream; 
and, besides, the stream is of insignificant size. 

DISCUSSION OF POSSIBLE CAUSES OF THIS AND SIMILAR DIS- 
ASTERS IN OTHER PARTS OF THE WORLD. 

It may said at the beginning of this discussion that while a definite 
conclusion has not been reached as to the cause or causes of this 



U. S. B. F.— Doc 



Plate III. 





VIEWS OF SAN CARLOS BEACH, SANIBEL ISLAND, NOVEMBER 19, 1916. 



U S, B F.— Doc 



Plate IV. 





VIEWS OF SAN CARLOS BEACH, SANIBEL ISLAND, NOVEMBER 19, 1916. 



MORTALITY OF FISHES, WEST COAST OP FLORIDA. 13 

mortality, yet certain possible causes are shown not to be operative. 
Furthermore, significant circumstances in the case of 1916 and of 
previous years, records of similar disasters in other parts of the 
world, and opinions of representatives of the numerous sciences con- 
cerned, are brought together here as the basis of discussion and also 
for further work, if there should be a recurrence of the phenomenon. 

The mortality occurred in 1844, 1854 (Ingersoll, 1882) , and a very 
severe attack was reported in January, 1878. In August, September, 
October, and November, 1880, it occurred again, but in relatively 
milder form. The last two instances are said to have been preceded 
by earthquakes. In July, 1882, the plague returned; in this case it 
may be connected with the tilefish disaster, which occurred at the 
edge of the continental shelf south of Nantucket along the 100- 
fathom line. In the summer of 1908 a similar mortality destroyed 
the sponge beds along the keys between Key West and the mainland. 
In 1916, as above stated, the mortality was exceedingly severe be- 
tween Boca Grande Pass and Big Marco Pass. The older reports are 
meager and not based on direct observations; in some cases inverte- 
brates — chiefly sponges and king crabs — were predominant, in others, 
sharks and porpoises. It may, then, be assumed that the reports 
furnish no reliable indication of exact conditions. 

The causes suggested are (1) water from the Everglades charged 
with tannin and products of decomposition of palmettoes and man- 
groves; (2) extraordinary abundance of Peridinium known to have 
occasioned the death of fishes in different parts of the world; (3) a 
disease, fungoid, parasitic, or bacterial ; (1) dilution of the water by 
unusually heavy rains; (5) an issue of gas, volcanic or natural; and 
(6) earthquakes or seaquakes. 

FOUL WATER FROM THE EVERGLADES. 

1. A hypothesis that has been advanced repeatedly is that water 
from the Everglades, charged with tannin and the products of decay 
in vegetation, is brought down by the rivers and kills fishes. It may 
be said with sufficient certainty that this is an impossible explana- 
tion. For there are no a priori grounds for assuming that the Ever- 
glade water is poisonous ; nor is there any material evidence of such 
a condition. No fresh-water fishes were killed ; life in the river was 
normal ; and fishes are known to live in the Everglades. The sporadic 
appearance of the phenomenon casts doubt on the possibility of such 
an explanation. And, finally, it seems quite impossible to believe 
that the volumes of the rivers are sufficient to accoimt for such a 
widespread distribution of the mortality. It may be, however, that 
the accumulation of the river load as a decaying organic sediment 



14 MORTALITY OF FISHES^ WEST COAST OF FLORIDA. 

furnishes the gases and other products of decomposition confined 
for a time, but sporadically released by what may be found to be the 
proximate cause — seismic disturbances. This possibility will be 
discussed later. 

PERIDINIUM AND OTHER PRGTISTS. 

2. An extraordinary abundance of Perldiniutn has, at times, caused 
the death of a great number of fish and Crustacea. Under certain 
circumstances, as yet unknown, these organisms multiply in vast 
numbers, giving the sea a reddish or chocolate color. Such colored 
areas are usually accompanied by an offensive smell, and are sharply 
marked off from the unaffected water. They have been encountered 
by mariners in many parts of the world, and numerous accounts ap.- 
pear in the literature. Darwin (1846) observed it "a degree south 
of Valparaiso," Nishikawa (1901) and Mitsukuri (1904) on the 
Japan coast. Carter (1858) around the island of Bombay, Mead 
(1898) in Narragansett Bay, Smith (1903) in Manila Bay. Both 
Darwin and Carter cite numerous other references. 

Dr. R. E. Coker records (in unpublished notes) from the coast of 
Peru a phenomenon possibly due to the same cause and commonly 
known as the "painter." This phenomenon has been described by 
Hutchinson (1873) thus: 

* * * There is an interesting peculiarity here * * * called the 
'■ painter," the palpable evidences of which consist in a changed color of the 
sea water (most generally to a muddy white), an odor most foetid, nauseous, 
and depressing, with the accompaniment of the white paint on ships and boats, 
inside as well as outside, becoming totally discolored and often partially 
black. * * * I am induced to attribute this emanation chiefly to submarine 
volcanic action, generating sulphuretted hydrogen gas. * * * Although met 
with at Callao, in its most aggravated form, the " painter " is likewise found 
along the coast as far as San Jose de Lambayeque, nearly 500 miles north. 
From the end of December imtil April is the time when the phenomenon 
mostly exists. 

I have before me an analysis of the sea water of Callao, bottled up during 
the existence of the " painter " and having some mud from the bottom of the 
bay contained therein. This was sent * * * to London, and was there 
analyzed by Mr. T. Keates. Mr. Keates reports that, after being allowed to 
rest, the water poured off proved to be sea water and that the black mud left, 
after the water had been decanted, was in a state of active decomposition, 
large quantities of sulphuretted hyrogen gas as well as sulphate [sic] of ammo- 
nia being given off. The black color of the mud was found to be owing to the 
presence of sulphate [sic] of iron which was formed as a result of the decom- 
position mentioned. Whilst this latter was due to the sulphur of the organic 
matter combining with the iron present in the mineral part of the mud, to 
produce the black sulphide [sic] * * *. 
1,000 parts of the mud dried at 230° F. yields : 

Water 769.6 

Dry mud 230. 4 



MORTALITY OP FISHES, WEST COAST OF FLORIDA. 15 

100 parts of the mud dried yielding by analysis : 

Organic matter 10. 50 

Chloride of sodium, alkaline sulphates, etc 6. 43 

Salts of lime ^ 3.75 

Alumina of [and?] oxide of iron [sic] 16.00 

Siliceous matter 63. 25 

Loss . 07 

* * * In the course of a few days I observed the water of the bay under 
four different aspects. 

First. Ochre-brown, with somewhat of a reddish tinge, and opaque. This, 
when examined under the microscope, showed animalculse of a spheroid or 
circular form and of lilxe color to the water. In 12 hours after it was — 

Second. Of a dark green, and still thick aspect, in which, by the microscope, 
was visible another class of animalculse of an hourglass form, round and broad 
at each end, but contracted at the center. Although there was but one drop 
of the water under the glass, a large number of these jumped about. 

Third. The next morning, or in 14 to 16 hours afterwards, the water was a 
muddyish white. This time the smell in the harbor was most pungently nause- 
ating. It is considered the true " painter " when white paint becomes black, 
and headaches are general, with everybody under its influence. No animalculre 
were visible througli the microscope in this state of affairs from the second to 
the third condition. I may add that in the intervening period we had a shock 
of earthquake at about 5 o'clock in the morning, and during the occurrence of 
which it may be conjectured submarine volcanic action destroyed all animal life 
of these insects seen two days previously. 

Fourtl). This is the ordinary water of Callao Bay. * * * 

From Hutchinson's description it would appear doubtful that this 
was Peridiniurn. Darwin's observations (1846) may help to clear 
this up : 

On the coast of Chile, a few leagues north of Concepcion, the Beaylc one day 
passed through great bands of muddy water exactly like that of a swollen 
river ; and again, a degree south of Valparaiso, when 50 miles from land, the 
same appearance was still more extensive. Some of the water placed in a glass 
was of a pale reddish tint and, examined under a microscope, was seen to 
swarm with minute animalculse darting about and often exploding. Their shape 
is oval and contracted in the middle by a ring of vibrating curved cilire. It was, 
however, very difficult to examine them with care, for almost the instant motion 
ceased, even while crossing the field of vision, their bodies burst. Sometimes 
both ends would burst at once, sometimes only one, and a quantity of coarse, 
brownish granular matter was ejected. The animal an instant before bursting 
expanded to half again its natural size, and the explosion took place about 15 
seconds after the rapid progressive motion had ceased ; in a few cases it was 
preceded for a short interval by a I'otatory movement on the longer axis. About 
two minutes after any number were isolated in a drop of water they thus 
perished. 

This may explain the ephemeral nature of the animalculse, and 
also, since they die in such vast numbers, it is not difficult to con- 
ceive the consequences of the decay of so much organic matter. 

Carter (1858) shoAvs that the various hues of sea water, as described, 
are due, at least around the, Island of Bombay, to one organism, Peri- 
diniwni sanguineum. In the swimming stage the organism is green 



16 MORTALITY OF FISHES, WEST COAST OF FLOEIDA. 

and translucent; as the transition time approaches, the chlorophyll- 
like substance responsible for the green color disappears, a red sub- 
stance takes its place and dissolves in oil globules that have been 
forming. At this stage it is red and visible to the naked eye. After 
only a iew days the individuals assemble, lose their red color, 
become encapsulated {Protococcus form), and sink or float on the 
surface. This stage is followed by a subdivision into tv^o or four 
new ones. This latter process may be repeated several times until 
eventually a ciliated form appears again, completing the life cycle. 
The latter form is covered by an excessively fragile shell which " is 
broken b}^ the pressure of the thinnest piece of glass." 

This description explains the varying color of the streaks, the 
periodicity, and it may explain the bursting observed by Darwin, 
if he used cover glasses in observing them. 

Could this have been the cause of the trouble in Florida? No 
evidence of the presence, in extraordinary numbers, of these organ- 
isms was found. When the water was described as red, further 
questioning brought out the fact that it was by transmitted light 
on the beach, and not by reflected light. Fishes observed while dying 
were in clear water. Still, the condition as described may have 
existed before the writer arrived, and the dissolved decomposition 
gases might have persisted in the water to an extent fatal to fishes 
after the organisms responsible had perished. Or the organisms 
might have become lost from view either by disintegration or by 
passing into the protococcus form and sinking, as suggested by 
Carter (1858). But such red water, to explain the conditions found, 
would have to be distributed over an unprecedentedly large area to 
persist for two months and yet escape detection by the many passing 
ships, and it would be necessary to explain the widely fluctuating 
periodicity, in some cases one year, in two other cases 24 and 25 
years, respectively. 

Gilchrist (1914) definitely ascribes certain , instances of mortality 
on the South African coast to Noctiluca and to diatoms. These 
forms, decaying in large numbers in the water, make the latter an 
unfit medium for fishes. Among the instances described by him as 
due to obscure causes, one is clearly due to Peridmiwn. 

DISEASE AND PARASITES. 

3. Evidence of disease or parasitism is likewise lacking, as is shown 
by the examination and dissection of specimens already described. 
On the other hand, it would be difficult to believe, without the most 
thoroughly convincing evidence, that so many species of animals 
could be affected by an epidemic of any single disease, or that such 



MORTALITY OP FISHES, WEST COAST OF FLORIDA. ' 17 

a disease would confine itself to a limited locality for the larger 
part of a century or perhaps a much longer period of unrecorded 
observation. 

DILUTION OF THE WATER. 

4. Dilution of the water hardly deserves serious consideration, for 
the phenomenon is not correlated with the rainy season or unusual 
discharge of the rivers. As shown by the table, the salinity does not 
indicate serious dilution of the water. Of course a dilution ade- 
quate to explain the mortality of fishes would concern only an excess 
of run-oif above the normal. The area of ocean concerned, in com- 
parison with the small rivers, at once negatives this hypothesis ; and 
if the water were sufficiently diluted, it may be assumed with good 
reason that unconfined fishes would seek their proper salinity by 
migration. 

VOLCANIC AND NATURAL GASES. 

5. It is now time to call particular attention to certain circumstances 
of prime importance that have served largely to destroy the fore- 
going suggested causes, and which can not be overlooked in arriving 
at a conclusion. They are (a) the irregular periodicity, both as to 
years and seasons; (h) the strictly marine aspect of the phenomenon; 
(c) the large area covered; (d) the definite limitation of this local- 
ity; (e) the limitation of the mortality to the animals, whose res- 
piration is performed by an oxygen carrier, haemoglobin, haemocyanin, 
etc. ; (/) the progressive southward appearance of the mortality. 

The irregular periodicity, the marine aspect, the area covered, and 
particularly the limitation to the region concerned all suggest a geo- 
logical explanation, whether the issue of a gas or the occurrence of 
an earthquake, fixed in one place, sporadic in outbreak, and inde- 
pendent of weather fluctuations. The species affected and the south- 
ward progress are not contradictory to such an explanation, as will 
be seen. 

Dr. T. W. Vaughan, of the United States Geological Survey, stated 
verbally to the writer that he saw only the remotest possibility of 
a volcanic gas in this region. The region is inactive volcanically, 
and the discovery of a volcanic fumarole would occasion great sur- 
prize to geologists. Beyond that w^e have nothing for or against 
volcanoes.' There is no question that volcanic gases would be deadly 
to fishes. For, while volcanoes emit different gases in different stages 
of their activity, the emissions always contain substances deadly to 
fishes, if nothing worse than carbon dioxide It is scarcely necessary 
to present data here as to the composition of such gases. Any chlo- 



18 MORTALITY OF FISHES, WEST COAST OF FLORIDA. 

rine, as h3'drochloric acid or as ammonium chloride, or in any 
soluble combination whatever, would certainly be detected by the 
chlorine determination (salinity) ; sulphur gases and carbon dioxide 
would alter the alkalinity of the water, though much would depend 
on the freshness of the water when the determinations were made. 
An unfortunate delay impaired the value of the samples collected; 
it was therefore impossible to determine whether or not these gases 
were present. 

Similar remarks concerning natural gas issues may be made. Such 
gases consist, of course, largely of the light paraffins, usually small 
quantities of olefines and occasionally some carbon monoxide. Little 
is known of the etfects of these gases on fish. The injury to man 
done by methane is done chiefly or entirely by the mere dilution of 
the air by this gas. Ethylene and ethane probably act in a similar 
manner. These gases are slightly soluble in water, ethylene to the 
extent of 4 per cent volume. In water these gases could not act as 
they do in air, for the solubility of a gas is quite independent of all 
other gases and as maich oxygen w^ould be present in a saturated so- 
lution of any of them as in their total absence. 

Of carbon monoxide more can be said. This gas acts as a poison 
to animals, whose respiration is dependent on a blood pigment by 
combining firmly with the pigment to the exclusion of oxygen ; while 
these animals situated in the presence of abundant oxygen and pre- 
senting a wide area of " semipermeable " skin, and whose respiration 
is performed by the agency of oxygen dissolved in the blood plasma, 
are immune, since carbon monoxide does not interfere Avith the pas- 
sage of oxygen into the body (Leitch, 1916). Carbon monoxide is 
soluble to a sufficient extent thus to interfere with respiration. It is 
therefore suggestive to note that all the animals killed, except sponges, 
were dependent on a blood pigment (haemoglobin, hajmocyanin, echi- 
nochrom, etc.). Sponges are the only animals observed on the 
beaches whose respiration is not dependent on one of these carriers 
or pigments, but sponges are often seen, even in normal times on the 
beaches. 

In February and March, 1894, the Albatross investigated and re- 
ported on a case of widespread mortality of fishes off the coast of 
California between Santa Barbara and San Diego. Evidences there 
obtained indicated petroleum and hydrocarbon gases as the cause of 
the disaster. Man}'^ species were killed, but those dead were chiefly 
flatfish and barracuda. The odor of petroleum was evident from the 
dead fish. The body slime was colored yellow in patches, and the gall 
bladder was ruptured. The oil springs said to exist off the coast were 
held responsible for the oil and gas issues. 



MOETALITY OF FISHES^ WEST COAST OF FLORIDA. 19 

EARTHQUAKES. 

6. Earthquakes kill fishes directly by concussion. Oldham (1899) 
cites the case of the destruction of fishes in the Sumesari River in 
India by the great earthquake of June 12, 1897. which killed " myri- 
ads as by the explosion of a dynamite cartridge." Xumerous other 
instances are cited by various authors. 

It is not evident in this case from the data at hand that earth- 
quakes killed the fishes directly by concussion. The following extract 
from a letter from the United States Weather Bureau bears on this 
point : 

Our records show that during 1916 there were no seismic disturbances of 
any considerable severity in tlie Gulf region. 

We have no precise earthquake records of that region for the earlier dates, 
1844 * * * 1908, but probably no severe ones occurred, as this is not an 
active seismic region. 

Further than this, the long duration of the mortality, the south- 
ward progress, and particularly the death of fishes under observation 
in the partly inclosed shallow Avater, entirely dismisses the hypothesis 
of direct injury by shock. 

It seems possible, however, that the incidental effects of earth- 
quakes might explain the death of the fishes. For instance, gases 
are sometimes emitted along with the shock. The following quota- 
tion from Darwin pertains to this aspect of the subject: 

In Capt. Fitz Roy's excellent account of the earthquake (Cliile, 1833, Jan. 
20), it is said that two explosions, one like a column of smoke and another like 
the blowing of a great whale, were seen in the bay. The water also appeared 
everywhere to be boiling ; and it became black and exhaled a most disagreeable 
sulphurous smell. These latter circumstances were observed in the Bay of 
Valparaiso during the earthquake of 1822 ; they may, I think, be accounted 
for by the disturbance of the mud at the bottom of the sea containing organic 
matter in decay. In the Bay of Callao during a calm day I noticed that as 
the ship dragged her cable over the bottom its course was marked by a line of 
bubbles. 

Prof. J. B. Woodworth, of the Harvard seismographic station, sets 
forth, in a letter of some length, a possibility which has not been con- 
sidered, and which seems worth investigating. The substance of his 
letter is as follows : 

Previous to the cases of 1908 and 1916 there are no satisfactory 
records of seismic activity in the region concerned. It may be quite 
possible, however, that unobserved shocks of low intensity could ex- 
plain the mortality ; that occluded gases, resulting from the decay of 
sedimentai:y organic matter, are released by a disturbance of the sedi- 
ment, under which circumstances the occluded gases would rise into 
the water, dissolve, and interfere with the life processes of fishes. 
Or, at the edge of the rather wide continental shelf in this region, a 



20 MORTALITY OF PISHES^ WEST COAST OF FLORIDA. 

seismic disturbance of low intensity might cause accumulated sedi- 
ments to slide off into abyssal water, similarly releasing occluded 
gases and also mixing up the mud with the water. It is known that 
microseisms (as Prof. Woodworth terms them) are radiated from 
this locality, and it is believed by some that they are due to the West 
Indian cyclonic storms. 

This seems to be the most promising hypothesis. It might be ex- 
pected that the water flowing into this region carries a large amount 
of organic matter leached from the abundant Florida vegetation and 
held in colloidal solution; that this organic matter, on striking sea 
water heavily charged with lime is flocculated and falls to the bottom 
on the uncommonly wide expanse of continental shelf in this region ; 
that as it accumulates on the bottom it decays anaerobically, yielding 
methane, hydrogen sulphide, possibly carbon monoxide, and other 
gases ; that these gases, as generated, are confined by the pressure, in- 
creasing sediment, and, perhaps by the limestone crust which appears 
to cover the bottom ; that an earthquake shock, even an unnoticeably 
mild one, would so disturb the sediment, or break the crust, as to 
release the occluded gases, and that these gases work, by various 
physiological and chemical means, the injury to fishes. These organic 
gases, being rare in sea water, would never be detected by the ordi- 
nary analyses. 

The work of Prof. J. P. McClendon at Tortugas, in the summer of 
1916, suggests that the marginal supply of oxygen in this region is 
not great. In a letter on the subject he says : 

I think probably lack of oxygen killed the fish. When the Pq of tropical sea 
water reaches about 7.5 there is no oxygen left in the water. At Tortugas the 
Ph was about 8.15 and there was about 4 cc. of oxygen per liter. 

It would, of course, be necessary to explain any deficiency of 
oxygen. 

ALKALINITY AND SALINITY OF THE WATER. 

These two determinations were made as being most likely to reveal 
any unusual condition of the water. The alkalinity is somewhat 
higher than that of pure sea water. Dole found this to vary betw^een 
0.00237 N and 0.00257 N; McClendon found the alkalinity at Tor- 
tugas in 1916 to lie between 0.0023 N and 0.0025 N, while the samples 
taken in the region under discussion had an alkalinity varying from 
0.00236 N to 0.00297 N. This may be explained by the large amount 
of fresh water flowing into the salt water in this region, which is 
generally rather strongly alkaline. The salinity is lower than that 
of pure sea water; this is likewise explained by the fresh water 
flowing in. 



MORTALITY OF FISHES, WEST COAST OF FLOEIDA. 



21 



It is noteworthy that the water in which the filejBish was seen to die 
was of the highest salinity and lowest alkalinity found. Otherwise, 
there seem to be no factors showing any striking correlation. 

The following are the results of such determinations as were made : 



Alkalinity and Salinity. 



Date. 


Fraction 

of normal 

alkali. 


Salinity. 


1916. 






Nov. 19 

Nov. 13 


0.00297 
. 00294 


o/oo 

29.94 

32.81 


Nov. 16 

Nov. 19.... 


. 00289 
. 00288 


31.52 
30.61 


Nov. 14 

Do 


.00282 
.00277 


33.93 
34.20 


Nov. 15 


. 00277 


32.96 


Prior to 

Nov. 13. 

Nov. 19 


.00272 
.00261 


33.10 
30.97 


Nov. 15-... 


.00260 


32.43 


Nov. 19 

Mean 


,00236 
. 00276 


31.98 
31.56 



Remarks. 



In shallow water at Bailey's wharf, Sanibel, where filefish died. 
Sanibel post-office wharf; surface; day before storm; sealed in glass; 

76.5° F. 
Sanibel post-office wharf; surface; day after storm; 65° F. ; very low tide. 
Bailey's wharf, Sanibel; 2 fathoms (bottom); 50 feet from pomt where 

filefish died; live mangrove snappers. 
One-half mile from Point Ybel Light, San Carlos Pass; 75° F. 
One and one-half miles from Point Ybel I^ight, San Carlos Pass; sample 

from surface; water 2 fathoms; 72.4° F. 
Place where mullet died, shallow water of Tarpon Bay; described by 

fisherman; 1^ hours before storm; 75.3° F.; live conchs; porpoises in 

water. 
Specimens submitted by West Coast Fish Co., Kitchins Island, Pine 

Island Sound. 
Bottom (2 fathoms) off Point Ybel Light wharf, Sanibel, IJ miles from 

point where filefish died; 65.4° F. 
Near Gulf mouth. Blind Pass; rising tide; surface sample; 2* fathoms 

water; 20 minuies before storm broke; 75.8° F.; probably pure Gulf 

water. 
Surf water on Gulf Beach. 



OTHER MORTALITIES DUE TO OBSCURE CAUSES. 

Other mortalities have occurred in different parts of the world, due 
to obscure causes. Austin H. Clark (1903) observed a mortality of 
fishes on the coast of Venezuela, which seems similar to that off the 
Florida coast. Nordenskiold (1882) noted dead Gadus polaris in the 
Siberian Polar Sea, which he supposes to have been killed by an in- 
sufficiency of oxygen, under the ice, where the fish were confined. 
Cold has unquestionably brought about the death of fishes in many 
parts of the world.*^ 

Gilchrist (1914) cites numerous mortalities on the South African 
coast in addition to those already cited, ascribed to Peridinium, 
Noctiluca, and diatoms, but altogether without satisfactory explana- 
tion. One, however, deserves particular mention. In this case (which 
repeats itself annually at Knysna) there was a narrow streak of 
yellowish water extending along the coast for miles, of a temperature 
about 10° F. lower than the blue ocean water farther out, which was 
clearly marked off from the yellowish water. The author attempts to 
explain this by the meeting off this coast of the Mozambique (warm) 

o On Feb. 2 and 3, 1917, a " freeze " occurred on both coasts of Florida, killing thou- 
sands of fishes. This cold wave is described by R. H. Fitch in a forthcoming paper of the 
Weather Bureau. 



22 MORTALITY OF FISHES^ WEST COAST OF FLORIDA. 

and the Antarctic (cold) currents by which tlie cold water is forced 
upward along the coast and is limited offshore by the w^arm current. 
The periodic nature of the phenomenon is, however, not explained. 

This mortality of fishes on the Florida coast may be of interest and 
importance in many respects. It would hardly be an exaggeration to 
assert that the number of fishes that perished w^ould be sufficient 
to supply the State of Florida for a season Yet a few w^eeks after 
normal conditions were restored we were informed that fishing on 
the Florida coast was as good as ever.*^ These facts give rise to the 
suggestion that, enormous as are the numbers of fishes in our coastal 
Avaters, natural causes may be quite as destructive to them as are the 
activities of man. 

The question has arisen repeatedly as to the means by which the 
strata, rich in fossils of fishes, were laid down. Instances like this 
and dozens of other in as many parts of the world readily answer the 
question. Large numbers of decaying animals may also have a bear- 
ing on the formation of other mineral beds — the phosphates, for 
example, that might be produced from the organic phosphorus. 

It is also true that, if this misfortune should occur again, valuable 
information may be gained concerning the presence and number of 
the various species of fishes, their winter habitat, distribution of sizes, 
etc., from a study of the dead fishes themselves. 

SUMMARY AND CONCLUSIONS. 

A mortality of fishes occurred on the coast of Florida from October 
3 to the last of November, 1916, appearing progressively southward 
from Boca Grande to Marco, and apparently killing representatives 
of all local species of fishes, but very few other aquatic animals, in 
the sounds inclosed by the keys and in the Gulf of Mexico for a dis- 
tance of 45 miles or more, but not affecting fresh- water forms. 
Meteorological conditions were normal. Post-mortems revealed noth- 
ing pathological in the fishes. The salinity of the water was some- 
what lower than that of normal sea water, and the alkalinity some- 
what higher. 

The cause of the mortality in this region, as has been stated, has 
not been determined. Foul water from the Everglades as a possible 
cause may be dismissed, as well as all meteorological conditions. 
A^olcanic action is highly improbable, and attention need not be 
turned to such a possibility from the evidence now at hand. Peri- 
dinii appear to furnish an exceedingly unlikely explanation, but 
it is, perhaps, proper to reserve judgment, as the e^■idences contrar-y. 
to such an explanation are not altogether convincing. A disease 

c Later reports (April. 1017) from the GrdiiiiiKs indicate tliat tlio tishing was poor 
throusli the winter season. 



MORTALITY OF FISHES, WEST COAST OF FLORIDA. 23 

seems to be a quite impossible explanation. Some geological, perhaps 
seismological explanation, such as Prof. Woodworth suggests, ap- 
pears to be the most promising possibility. 

Aside from the continued recurrence of the phenomenon in the 
past, we have no data on which to base a prediction as to futvire 
recurrences. In the event of a verification of the seismological- 
sedimentary hypothesis, a recurrence may be expected sometime. 
In such an event oceanographic methods should be resorted to at 
the first indication of the trouble; in the meantime a collection of 
bottom and water samples over the region is desirable, and, if pos- 
sible, gas bubbles, if present, should be collected from the mud by 
appropriate apparatus. 

BIBILIOGRAPHY. 

Carter, H. J. 

1858. Note on the red coloring of the sea round the shores of the Island 
of Bombay. Annals and Magazine of Natural History, vol. i, 3d 
ser., no. 4, art. xxiii, p. 258-262, April, 1S5S. London. 
Clark, Austin H. 

1903. Notes on the habits of certain Venezuelan b'rds. The Auk. vol. xx, 

no. 3, July, 1903, p. 285-286. Cambridge. 
Darwin, Charles. 

1846. Researches into the natural history and geology of the countries 
visited during the voyage of H. M. S. Beagle round the world, under 
the command of Capt. Fitz Roy, R. N., vol. i, chap, i, journal of 
Mar. 18, 1832. p. 18-23. New York. 
Gilchrist, .T. D. F. 

1914. An inquiry into the fluctuations in fish supply on the South African 
coast. Union of South Africa, Province of the Cape of Good Hope, 
Slarine Biological Report no. ii, for the year ending .Txuie 30, 1914, 
art. II, p. 8-35. Cape Town. 
Hutchinson, Thomas J. 

1873. Two years in Peru, with exploration of its antiquities, vol. i, chap. 
XI, p. 219-225. London. 
Ingersoll, Ernest. 

1882. On the fish mortality in the Gulf of ^Mexico. Proceedings of the 
United States National Museum, vol. iv, for 1881, p. 74-80. Wash- 
ington. 
Leitch, I. 

3916. The function of Iueniogl()l)in in invertel)rates. with special reference to 
PJanorhis and Chirononius larv?e. Journal of Physiology, vol. l, no. 
6, p. 370-379. London and Cambridge. 
Mead, A. D. 

1898. Peridinium and the " red water " in Narragansett Bay. Science, n. s., 
vol. VIII, no. 203, p. 707-709. Nov. 18, 1898; Garrison. (Also noted 
in Report, United States Commissioner of Fish and Fisheries. 1899, 

p. CXLII.) 
MiTSUKURI, K. 

1904. The culture of marine and fresh-water animals in Japan. Bulletin of 

the United States Bureau of Fisheries, vol. xxiv, p. 884. Wash- 
ington. 



24 



MORTALITY OF FISHES^ WEST COAST OF FLOEIDA. 



NiSHIKAWA, T. 

1901. Gonyaulax and the discolored water of the Bay of Agu. Annotationes 
Zoologicae Japoneuses, vol. v, pt. i, p. 31. Tokyo. 

NORDENSKIOLD, A. E. 

1882. The voyage of the Vega round Asia and Europe, M'ith a historical 
review of previous journeys along the north coast of the Old World. 
Translated by Alexander Leslie, p. 246-247. New York. 
Oldham, R. D. 

1899. Report on the great Indian earthquake of June 12, 1897. Memoirs of 
the Geological Survey of India, vol. xxix, p. SO. Calcutta. 
Smith, Hugh M. 

1903. Peridinium. (Editorial article containing an extended quotation froii' 
Dr. Smith.) Philippine Journal of Science, vol. in, no. 3, p. 187. 
Manila. 
Tan NEK, Z. L. 

1896. Report upon the operations of the United States Fish Commission 

steamer Albatross for the year ending June 30, 1894. Report of 

the Commissioner for the year ending June 30, 1894, p. 217-218. 

Washington. 

Brief notes have appeared in the publications of the Bureau of Fisheries m 

previous years as follows: Rathbun, Richard (Fisheries and Fishery Industries. 

sec. V, vol. II, p. 831). Newspaper clipping (Bulletin, vol. ii, 1882, p. 104). 

H. D. Pierce (letter, Bulletin, vol. iv, 1884, p. 264). Smith, H. M. (Bulletin, 

vol. XVII, 1897, p. 234.) Moore, H. F. (Bulletin, vol. xxviii, pt. i, 1908, p. 434). 

Report for 1886 (p. 68-72). 



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